There is a demand for a device that transfers signals using light, such as a photo-coupler or an optical data link, to reduce power consumption in the light-receiving circuit. For example, an analog receiver circuit which includes, at an input stage thereof, a light receiving element and a trans-impedance amplifier (TIA) consumes much power since current flows while inputting no signal. In contrast, a digital circuit made up of metal-oxide-semiconductor field-effect transistors (MOSFET) enables power consumption to be reduced.